1. Field of the Invention
The present invention relates to a method of producing vehicle lamps. More particularly, the present invention relates to the art of ensuring that two members including an inner lens are joined together with an improved external appearance in the method of producing a vehicle lamp having the inner lens disposed inside an outer lens such that the inner lens covers an area narrower than the outer lens and that two members including the inner lens are joined together by laser welding.
2. Related Art
In producing a vehicle lamp having an inner lens disposed inside an outer lens such that the inner lens covers an area narrower than the outer lens, the inner lens has heretofore been fitted to the outer lens by ultrasonic welding or fixed to a body by lance mating, for example.
When the inner lens is joined to the outer lens by ultrasonic welding as described above, there has existed a problem of deteriorating the external appearance of the lenses in that the weld between the outer lens and the inner lens is seen through the outer lens, that the compatibilized portion between the outer lens and the inner lens is jutted out aside or that the jutted-out portion is seen through the outer lens. In the case where an inner lens and a body are injection-molded pieces, when the inner lens is fitted to the body by lance mating, the presence of an overlapped portion in the direction in which the mold like a lance is taken out makes a hole for taking out the mold in the rear of the portion above (in the direction in which the mold is taken out). Consequently, the portion on the back side of the lighting device is seen through the hole, which also deteriorates the external appearance.
In addition, there also develops a problem of taking time for assembly work and machining under the prior art method described above.